Visual scanning and recognition of ambiguous faces in children with autism: The effects of morphing levels and facial identities

Abstract

Background and aimPrior work on face processing in children with autism spectrum disorder (ASD) has mainly focused on the investigation of unfamiliar faces. The present study aimed to extend earlier research by the inclusion of the different faces with varying levels of perceptual difficulty. MethodsWe employed eye-tracking and morphing techniques to measure face recognition involving identification of face morphs and to record eye movements during the task. Three groups of children participated in the study, comprising 24 with ASD (aged from 4 to 7 years), 25 verbal IQ (VQ)-matched typical developing (TD) controls (aged from 3 to 4 years), and 25 chronological age (CA)-matched TD controls (aged from 4 to 6 years). ResultsThe group-difference was specific for morphed unknown faces – ASD children had a decreased judgement of unknown faces and showed a lower specificity. Concurrent eye-tracking further provided mechanistic insights: the ASD group exhibited a significant reduction in eye-region fixation when recognizing ambiguous unknown faces, relative to both TD groups. ConclusionThe current study provides evidence of a selective difficulty in the identification of unknown faces in ASD when the perceptual demand increased, without atypicality in self and familiar face processing. Reduced attention and social interest may be responsible for difficulties in response to stranger faces in young ASD children, rather than a consequence of inability.